Two-dimensional fluidic logic device

ABSTRACT

A pair of opposing airstreams impact within a rectangular chamber having opposed stream-confining sidewalls. A pair of opposite impacting streamflows are established and flow into a pair of passageways provided in the first sidewalls with each passageway having axially spaced planar lock-on walls to one of which the impacting streamflow attaches as a result of fluid entrainment. Control passageways and related output passageways are connected to the chamber in one of said first walls to the opposite sides of the passageways. Main stream bleed passageways are connected to the opposite sides of the first impact flow passageway in the second or opposite of the first sidewalls. The impacting flow lock-on to the corresponding planar walls of the first bleed passageways results in flow and pressure in the corresponding output passageway. A control stream applied to one main stream associated with the free lock-on wall reduces the stream strength to shift the impact flow to the opposite lock-on walls and an output is created in the other output passageway.

United States Patent [72] inventor Warren A. Lederman Milwaukee, Wis. [21] Appl. No. 5,652 [22] Filed Jan. 26, 1970 [45] Patented [73] Assignee Dec. 7, 1971 Johnson Service Company Milwaukee, Wis.

[54] TWO-DIMENSIONAL FLUIDIC LOGIC DEVICE 9 Claims, 3 Drawing Figs.

3,520,316 7/1970 Colston ABSTRACT: A pair of opposing airstreams impact within a rectangular chamber having opposed stream-confining sidewalls. A pair of opposite impacting streamflows are established and flow into a pair of passageways provided in the first sidewalls with each passageway having axially spaced planar lock-on walls to one of which the impacting streamflow attaches as a result of fluid entrainment. Control passageways and related output passageways are connected to the chamber in one of said first walls to the opposite sides of the passageways. Main stream bleed passageways are connected to the opposite sides of the first impact flow passageway in the second or opposite of the first sidewalls. The impacting flow lock-on to the corresponding planar walls of the first bleed passageways results in flow and pressure in the corresponding output passageway. A control stream applied to one main stream associated with the free lock-on wall reduces the stream strength to shift the impact flow to the opposite lockon walls and an output is created in the other output passageway.

Control PATENIED DEC 1 IBTI 7 FIGJ FIG-2 37 Contlol INVENTOR.

WARREN A. LEDERMAN Attornevs TWO-DIMENSIONAL FLUIDIC LOGIC DEVICE BACKGROUND OF INVENTION This invention relates to a two-dimensional fluidic device and particularly to a flip-flop-type logic device employing interacting fluid streams.

Fluidic devices employing interacting fluid streams to produce functions heretofore generally obtained only with electronic devices have been developed and applied in control and processing systems in recent years. A logic element or device which is widely employed in control and data processing systems is a flip-flop-type device and particularly of the set and reset construction wherein the logic circuit has either of two stable output positions responsive to the proper inputs. A fluidic flip-flop unit of the set-reset flip-flop type with bistable fiuidic amplification to yield a high-pressure recovery signal in combination with a high input signal impedance is disclosed in the copending application of Louis D. Atkinson entitled Fluidic Logic Device filed on the same date as this application and assigned to the same assignee. The fluidic flip-flop device disclosed therein is a three-dimensional unit having impacting streams with the impacting position of the streams occurring within a reference chamber between a pair of output chambers and orifices, one to each side of the impacting position. The reference chamber includes a lateral impacting flow passageway having parallel planar walls extending from the output orifices such that with the impacting position immediately adjacent a related orifice and wall, the impacting emitted or flow stream locks to the adjacent wall as a result offluid entrainment phenomena.

The formation of the lock-on in proximity to the one collector wall and orifice, results in the flow exiting from the corresponding output passageway such that a significant portion of the supply pressure level is recovered as a useful output flow signal.

A control stream is applied to the main stream within the reference or control chamber via the control signal passage way associated with the free lock-on wall in such a manner as to cause an alteration in the velocity profile of the corresponding main supply stream and a reduction in the strength of the related stream with respect to the opposed main stream. This results in a temporary pressure imbalance resulting in the shifting of the impact position from the one collector wall to the opposite wall. This establishes a highly satisfactory and reliable set-reset flip-flop fluidic device.

SUMMARY OF INVENTION The present invention is particularly directed to a twodimensional fluidic logic device providing a flip-flop function and generally includes a pair of opposing impacting streams with the impacting streamflow established within a twodimensional control chamber wherein the streams are spaced from first spaced and opposite chamber walls and thus are free streams on two opposite surfaces and are confined by second chamber walls on the surfaces normal thereto. A pair of impact flow bleed passageways are provided in the first walls in alignment with the impacting stream flow with each passageway having axially spaced walls formed to define lockon walls to which the impacting streamflow attached as a result of fluid entrainment. A first control passageway and a related first output or collector passageway are connected to the chamber in one of said first walls to one side of said bleed passageways and a second control passageway and a related second output or collector passageway are similarly provided in the same wall to the opposite side of said bleed passageways. The collector passageways are formed immediately adjacent the reference passageways and the control passageways are located between the main stream orifices and the collector passageways. Main stream bleed passageways are connected tothe opposite sides of the first impact flow passageway in the second or opposite of said first walls.

The lock-on of the impacting flows to the corresponding lock-on walls of the impact flow bleed passageways results in a pressure and flow in the immediately adjacent output passageway. Aspiration is established in the opposite half of the device by the corresponding main stream as the control passageway and bleed passageway prevent saturating of the corresponding half of the reference or control chamber. The impact flow is shifted to the opposite corresponding lock-on walls with a resulting pressure and flow in the second output passageway by temporarily changing the relative strength of the main streams to overcome the lock-on forces.

The present invention thus provides a highly improved twodimensional flip-flop-type fluidic logic device which can be readily fabricated. The impacting stream principle produces a high input signal impedance, as well as isolation between the input and output signals.

BRIEF DESCRIPTION OF DRAWING The drawing furnished herewith illustrates the best mode presently contemplated by the inventor for carrying out the subject invention and clearly discloses the above advantages and features as well as others which will be readily understood by those skilled in the art from the description of the illustrated embodiment.

In the drawing:

FIG. 1 is a side elevational view of a two-dimensional, fluidic logic unit in accordance with the present invention;

FIG. 2 is a vertical section taken generally on line 2-2 of FIG. I; and

FIG. 3 is a view similar to FIG. 2 showing the alternate output position of the logic unit.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring to the drawing, the illustrated fluidic flip-flop logic unit is of a two-piece construction including a recessed base I having a cover 2 to define a plurality of selected twodimensional internal passageways. The cover 2 is secured in any suitable manner, as by screws 3, in fluidtight engagement to base I. The base 1 is symmetrically formed about the centerline with a pair of main stream supply nozzles 4 and 5 to the opposite sides thereof. The nozzles 4 and 5 extend inwardly from the outer side edges of base I and terminate in similar main stream forming orifices or apertures 6 and 7 in aligned, longitudinally spaced relation. The main stream orifices 6 and 7 terminate in the opposite end walls ofa reference or control chamber 8 and the nozzles 4 and 5 are connected to a suitable fluid supply to establish opposing streams 9 and 10 within chamber 8.

The fluids employed herein may be a gas, liquid, or a mixture thereof. Air is preferably employed because of the ready availability of air and convenience of referencing of such a system to the atmosphere.

The members l and 2 may be similarly constructed in any suitable manner such as molding of the parts of a suitable plastic or the like or machining of the appropriate passageways and chambers as generally rectangular recesses in the surface of body member 1. The chamber 8 is particularly formed as a rectangular chamber by a recess having a depth corresponding to that of apertures 6 and 7 and a substantially greater width such that the main streams 9 and 10 are confined by the base wall and cover 2 which define a pair of first sidewalls, but are essentially free streams in the opposite direction as a result of the spacing of the second sidewalls of chamber 8.

A pair of reference or bleed passageways 11 and 12 extend outwardly from the central portion of the reference chamber 8 to define an exit passageway means for the impacting streamflows or streams l3 and 14. Passageways 11 and I2 are preferably referenced to atmosphere or the like to essentially isolate the output and the input signals. The base 1 with the passageways formed by appropriate recesses in the one surface in combination with the cover 2 define a two-dimensional flow pattern within the reference chamber 8. The base of the recesses and the inner planar surface of cover 2 thus confine the stream in the corresponding planes. The reference chamber 8 is wider than the orifices 6 and 7 and by appropriate referencing, the streams 9 and 10 are essentially free streams in the one direction. As a result, the pair of impacting streams l3 and 14 flow in opposite lateral directions at the point of impact into the oppositely deposed bleed passageways 11 and 12.

The corresponding walls and 16 of the passageways 11 and 12 define suitable stream lock-on walls and are shown as flat, planar walls to which the impacting streamflows l3 and 14 attach by entrainment phenomena of the impacting streamflow.

The initial formation of the streams 7 and 9 is such that the emitted impacting streamflows l3 and 14 are angularly oriented with an outer peripheral portion contacting the lockon walls 15 and 16. This defines corresponding cavities l7 and 18 between the boundary of the adjacent supply streams and the walls 15 and 16 within which is formed a separation bubble which is below the reference or atmospheric pressure. The result is an entrainment or aspiration fluid within the bubbles l7 and 18 from the main streamflow generally in accordance with a vonextype phenomena. This is accompanied by a decrease of static pressure within the bubble thereby serving to hold the impacting streamfiows onto the walls 15 and 16 with a resulting latching or attachment phenomena. The streamflows l3 and 14 remain in this stable condition in the absence of a selected change in the relative strength of the main supply streams.

if the relative strength of the main supply stream 9 is increased relative to the opposed stream 10 by a predetermined amount, the strength of stream 9 overcomes the lock-on forces established by the interaction of the impacting streamflows l3 and 14 and the adjacent collector walls 15 and 16 to release the flows from such walls. When the pressure difference is such as to cause release of the streamfiows l3 and 14, the relative stream strength is also sufficient to cause such impacting flow to reverse and engage the opposite wall and create a lock-on to the opposite wall in a similar manner.

In the two-dimensional construction, output passageways 19 and 20 are provided to the corresponding one side of the main streams 9 and 10 and to the opposite sides of the bleed passageway 11. The output passageways 19 and 20 are shown similarly formed with relatively small output orifices or apertures 21 and 22 extending perpendicularly from the reference chamber 8 and then angularly fanning outwardly to the outer top edge of the body 1. The output apertures 21 and 22 are spaced only slightly from the bleed passageway 11 as shown by the narrow dividing walls 23 and 24 respectively. With the impacting streamflows l3 and [4 locked to the walls of 15 and 16, an output is established in the passageway, as shown in FIG. 2. To enhance the total lock-on effect, the edges of the chamber 8 intersecting with the center bleed passageway 12 are removed in a generally concave configuration as at 25. This promotes and strengthens the entrainment of boundary fluid and positive lock-on of the impacting stream 14 to the corresponding wall 16.

The relatively close placement of the output orifices is desirable to promote recovery of a substantial proportion of the output pressure. For the same reason, the corners of the dividing walls 23 and 24 are not removed. The relative strength of the main streams 9 and 10 is controlled by cor responding control signal passageways 26 and 27 which terminate in control stream orifices or apertures 28 and 29 immediately adjacent to the corresponding opposite outermost end walls of the reference chamber 8 and thus immediately adjacent the input nozzles 6 and 7 of the supply passageways 4 and 5. The control apertures 28 and 29 must be formed to the same side of the chamber 8 as the output apertures and are spaced axially outwardly thereof. The control passageway 26 extends inwardly from a supply input connection at the edge of body 1 and then downwardly with a reducing cross section to the control aperture 28. The aperture 28 is preferably provided with a reverse angular orientation such that a control stream therefrom includes a small component of force opposed to the axial flow and force of the main stream 9.

The control passageway 27 and orifice 29 are similarly formed in the opposite half of the body 1 with the orifice 29 similarly angularly oriented with a component of the signal stream when applied thereto opposing the main stream 10.

The unit may be constructed to initially establish the condition shown in FIG. 2. If the supply pressure at the supply orifice 7 is slightly larger than that at the supply orifice 6, the lateral flows l3 and 14 will tend to be slightly cone-shaped with a bias toward the walls 15 and 16. The impacting flows l3 and 14 engage lock-on walls 15 and 16 with the formation of the lock-on bubbles l7 and .18. correspondingly, the output pressure will build up within the chamber 8 and output passageway 19 and provide a corresponding signal. Some of the pressure may also back up into the control orifice or aperture 28 and passageway 26.

If a control signal is applied to the control passageway 27, a control stream 30 is established direction into lateral and opposing engagement with the main stream 10. The signal stream 30 deflects and changes the velocity profile of stream 10 with a relative reduction in the strength of the stream 10 with respect to the opposing stream 9. If the reduction is sufficiently great, the relative force tending to move the impact position to the right overcomes the lock-on force established by the entrainment phenomena or the like between fiows l3 and 14 and the engaged walls 15 and 16 results in shifting of the impact position within the chamber 8 and release of fiows l3 and 14 from walls 15 and 16. Furthermore, the lateral impacting flow l3 and 14 will then be in the cone-shaped opposite direction such as to engage the opposite walls 31 and 32 of the two bleed reference passageways. The lateral flow l3 and 14 will now lock to these walls 31 and 32 as shown in FIG. 3 and establish a second stable state.

The impacting stream flows l3 and 14 are stabilized by partial venting of the chamber 8 while permitting creation of an output pressure within the chamber 8 adjacent the lock-on wall then engaged by the lateral fiow l3 and 14. In the illustrated embodiment of the invention, bleed passageways 33 and 34 are similarly provided to the opposite sides of the bleed passageway 16 and each is similarly formed with a relatively narrow end defining an aperture or orifice 35 and 36 in the lower sidewall of the chamber 8 in FIGS. 2 and 3 and extending outwardly therefrom to the lower edge of the body 1 and are also preferably referenced to atmosphere or the like. The passageway apertures 35 and 36 are similarly spaced from the passageway 12 by a distance somewhat greater than the spacing of the output passageway apertures 21 and 22. In the illustrated embodiment of the invention, apertures 35 and 36 are shown generally aligned with and overlapping with the axially outermost portion of the output aperture and thus generally centrally of the wall between the supply orifices 6 and 7 and the reference passageways 11 and 12.

Applicant has found that the location of the output orifice closely adjacent to the bleed passageways and the control apertures to the same side of the output passageways and spaced outwardly therefrom in combination with the general centrally located bleed passageway apertures to the opposite side of the chamber 8 results in a highly satisfactory and reliable two-dimensional impact modulator device of a bistable output.

Thus, other arrangements such as placement of the output and the bleed reference to the same side may tend to promote or establish a pressure imbalance with respect to the pressure distribution about the supply nozzle axis with an axial rotation and shifting of the impact position in the absence of a control signal. Further, the relative size of the several orifices and apertures is highly significant with respect to optimum performance characteristics, If the relative size of the output aperture or bleed aperture is excessively enlarged, functional operation may be completely disrupted.

in the operation of the structure, each of the possible alternate states is a stable condition as the impacting streamflows remain locked to the corresponding wall even after removal of the input signal stream which promotes the desired switching. Further, the impact position is not disturbed by consecutive input signals on the same control passageway and only responds to complementary input signals alternately applied to the two control tubes. The illustrated embodiment of the invention defines a bistable amplifier of a two-dimensional construction employing the impacting streams concept and controlled completely by pure fluid streams and without mechanical or other components. The amplification results from the control by the relatively low-pressure signal stream of the relatively high-pressure main streams which, in turn, provide the relatively high output pressure.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims which particularly point out and distinctly claim the subject matter which is regarded as the invention.

lclaim:

l. A fluidic logic element comprising, a control chamber having first sidewalls and second connecting sidewalls and end walls, said end walls each having a main stream forming aperture, said main stream apertures establishing a pair of impacting streams confined by said first sidewalls and spaced from said second sidewalls and establishing a pair of opposite lateral impacting flows within said chamber, a pair of impact bleed reference passageways one in each of said second sidewalls in alignment with said lateral flow positions and including a lockon wall means in at least one of said passageways with the impacting streamflow locked on to such wall by fluid entrainment with the impacting streamflow adjacent said wall, output apertures in a first of said second sidewalls to the opposite sides of the corresponding bleed passageway, and control aperture means in the first of said second sidewalls providing control signal streams to control the relative strength of said streams to selectively overcome said entrainment force and move said impacting flow from the lock-on wall means.

2. The fluidic logic element of claim 1 having main stream bleed passageway means in the second of said second sidewalls referencing said pair of impacting streams to a reference pressure.

3. The fluidic logic element of claim 1, wherein the opposite axially spaced walls of said impact bleed passageway extending from the first of said second sidewalls each defines a lockon wall with the corresponding lateral impacting flow locked to one of such walls by fluid entrainment with the impacting streamflow adjacent such wall, and said control aperture means controlling the relative strength of said streams to selectively overcome said entrainment forces and move said impacting stream between the first and second lock-on walls.

4. The fluidic logic element of claim 1, wherein said control aperture means includes an aperture angularly oriented with respect to said main streams to establish a signal stream having a velocity vector opposing the corresponding main stream.

5. The fluidic logic element of claim 1 wherein said chamber is an elongated rectangular chamber having said end walls at the opposite ends of the longest chamber dimension, said pair of impact bleed passageways being aligned with each other and each including axially spaced lock-on walls to the opposite sides of the impacting streamflow, said output apertures being located immediately adjacent the impact bleed passageway, said control aperture means including a pair of apertures being located one each outwardly of a corresponding one of said output apertures and bleed passageway means in the second of said second sidewalls to the opposite sides of the corresponding impact bleed passageway and referencing said pair of impacting streams to a reference pressure.

6. The fluidic logic element of claim 1 wherein said chamber is an elongated rectangular chamber having said end walls at the opposite ends of the longest chamber dimension, said pair of impact bleed passageways being aligned with each other and each including axially spaced lock-on walls to the opposite sides of the impacting streamflow, said output apertures being located immediately adjacent the impact bleed passageway, said control aperture means including a pair of apertures located one each outwardly of said output apertures, said bleed passageways in the second of said second sidewalls being connected to said chamber with concave comer junctions to enhance said entrainment force between impacting flow and the corresponding lock-on walls, and bleed passageway means in the second of said second sidewalls referencing said pair of impacting streams to a reference pressure.

7. The fluid logic element of claim 6 wherein said lastnamed bleed passageway means are generally centrally located with respect to the corresponding output aperture and control aperture in the first of said second walls.

8. The fluidic logic element of claim 1 wherein said control chamber is a rectangular chamber having a substantially greater length between said end walls than between said first and second sidewalls, the cross section of said apertures and passageways being rectangular, said pair of bleed passageways being aligned with each other and each including axially spaced planar lock-on walls with the impacting streamflow locked on to one of the walls by fluid entrainment with the impacting streamflow adjacent the corresponding wall, and said control aperture means including a pair of control apertures being located one each adjacent said main stream forming apertures, and having main stream bleed passageways of a rectangular cross section in the second of said second sidewalls referencing said pair of impacting streams to a reference pressure, said main stream bleed passageways being generally aligned with the corresponding output apertures.

9. The fluidic logic element of claim 8, wherein said control apertures are angularly oriented with respect to said main streams to each establish a signal stream having a velocity vector opposing the corresponding main stream. 

1. A fluidic logic element comprising, a control chamber having first sidewalls and second connecting sidewalls and end walls, said end walls each having a main stream forming aperture, said main stream apertures establishing a pair of impacting streams confined by said first sidewalls and spaced from said second sidewalls and establishing a pair of opposite lateral impacting flows within said chamber, a pair of impact bleed reference passageways one in each of said second sidewalls in alignment with said lateral flow positions and including a lock-on wall means in at least one of said passageways with the impacting streamflow locked on to such wall by fluid entrainment with the impacting streamflow adjacent said wall, output apertures in a first of said second sidewalls to the opposite sides of the corresponding bleed passageway, and control apeRture means in the first of said second sidewalls providing control signal streams to control the relative strength of said streams to selectively overcome said entrainment force and move said impacting flow from the lock-on wall means.
 2. The fluidic logic element of claim 1 having main stream bleed passageway means in the second of said second sidewalls referencing said pair of impacting streams to a reference pressure.
 3. The fluidic logic element of claim 1, wherein the opposite axially spaced walls of said impact bleed passageway extending from the first of said second sidewalls each defines a lock-on wall with the corresponding lateral impacting flow locked to one of such walls by fluid entrainment with the impacting streamflow adjacent such wall, and said control aperture means controlling the relative strength of said streams to selectively overcome said entrainment forces and move said impacting stream between the first and second lock-on walls.
 4. The fluidic logic element of claim 1, wherein said control aperture means includes an aperture angularly oriented with respect to said main streams to establish a signal stream having a velocity vector opposing the corresponding main stream.
 5. The fluidic logic element of claim 1 wherein said chamber is an elongated rectangular chamber having said end walls at the opposite ends of the longest chamber dimension, said pair of impact bleed passageways being aligned with each other and each including axially spaced lock-on walls to the opposite sides of the impacting streamflow, said output apertures being located immediately adjacent the impact bleed passageway, said control aperture means including a pair of apertures being located one each outwardly of a corresponding one of said output apertures, and bleed passageway means in the second of said second sidewalls to the opposite sides of the corresponding impact bleed passageway and referencing said pair of impacting streams to a reference pressure.
 6. The fluidic logic element of claim 1 wherein said chamber is an elongated rectangular chamber having said end walls at the opposite ends of the longest chamber dimension, said pair of impact bleed passageways being aligned with each other and each including axially spaced lock-on walls to the opposite sides of the impacting streamflow, said output apertures being located immediately adjacent the impact bleed passageway, said control aperture means including a pair of apertures located one each outwardly of said output apertures, said bleed passageways in the second of said second sidewalls being connected to said chamber with concave corner junctions to enhance said entrainment force between impacting flow and the corresponding lock-on walls, and bleed passageway means in the second of said second sidewalls referencing said pair of impacting streams to a reference pressure.
 7. The fluid logic element of claim 6 wherein said last-named bleed passageway means are generally centrally located with respect to the corresponding output aperture and control aperture in the first of said second walls.
 8. The fluidic logic element of claim 1 wherein said control chamber is a rectangular chamber having a substantially greater length between said end walls than between said first and second sidewalls, the cross section of said apertures and passageways being rectangular, said pair of bleed passageways being aligned with each other and each including axially spaced planar lock-on walls with the impacting streamflow locked on to one of the walls by fluid entrainment with the impacting streamflow adjacent the corresponding wall, and said control aperture means including a pair of control apertures being located one each adjacent said main stream forming apertures, and having main stream bleed passageways of a rectangular cross section in the second of said second sidewalls referencing said pair of impacting streams to a reference pressure, said main stream bleed passageways being generally aligned with thE corresponding output apertures.
 9. The fluidic logic element of claim 8, wherein said control apertures are angularly oriented with respect to said main streams to each establish a signal stream having a velocity vector opposing the corresponding main stream. 